Melt Flow Rate Tester

Application

Melt Flow Rate Tester is used for the determination of the melt mass-flow rate (MFR) and the melt volume-flow rate (MVR) of thermoplastic materials under specified conditions of temperature and load. It includes two test procedures of mass-measurement method and displacement-measurement method. Melt Flow Rate Tester can be used to test engineering plastics with high melting temperatures, such as polyethylene, Polyarylsulfone, fluoroplastics, nylon, etc. It is also applicable for plastics with lower melting temperatures, including polyethylene, polystyrene, polypropylene, ABS resin, polyoxymethylene resin, etc.

Test Principle

The melt mass-flow rate (MFR) and the melt volume-flow rate (MVR) are determined by extruding molten material from the cylinder of a plastometer through a die of specified length and diameter under preset conditions of temperature and load. For measurement of MFR (procedure A), timed segments of the extrudate are weighed and used to calculate the extrusion rate, in grams per 10 min.

For measurement of MVR (procedure B), the distance that the piston moves in a specified time or the time required for the piston to move a specified distance is recorded and used to calculate the extrusion rate in cubic centimeters per 10 min. 

MVR can be converted to MFR, or vice versa, if the melt density of the material at the test temperature is known.

Standard

ISO 1133-2, ISO 1133-1, ASTM D1238, GBT 3682.1, GBT 3682.2, GB/T18742, JB/T 5456

Melt mass-flow rate or MFR

Rate of extrusion of a molten resin through a die of specified length and diameter under prescribed conditions of temperature, load, and piston position in the cylinder of an extrusion plastometer, the rate being determined as the mass extruded over a specified time

MFR is expressed in units of grams per 10 min. Alternative units accepted by SI are decigrams per minute, where 1 g/10 min is equivalent to 1 dg/min.

melt volume-flow rate or MVR? 

Rate of extrusion of a molten resin through a die of specified length and diameter under prescribed conditions of temperature, load and piston position in the cylinder of an extrusion plastometer, the rate being determined as the volume extruded over a specified time

MVR is expressed in units of cubic centimeters per 10 min.

"Load" in MFR and MVR testing? 

The Load” in MFR and MVR testing means the combined force exerted by the mass of the piston and the added weight, or weights, as specified by the conditions of the test.

Nominal Loads used in the testing are usually 0.325kg, 1.200kg, 2.160kg, 3.800kg, 5.000kg, 10.000kg, 21.600kg